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CVE-2021-40830

27
FAUCET Score

CVE-2021-40830 is a high-severity vulnerability (CVSS 8.8) affecting AWS IoT Device SDK v2 for Java, Python, C++, and Node.js on Unix systems, as well as AWS-C-IO. It allows an attacker to bypass CA pinning by exploiting how the SDK appends user-supplied Certificate Authorities (CAs) instead of overriding them, enabling spoofing of the MQTT broker. This attack requires access to a host's trust stores or compromise of a CA within them, along with DNS spoofing, potentially leading to data interception or manipulation. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
0.10.4CPE matchmatch criteria
cpe:2.3:a:amazon:amazon_web_services_aws-c-io:0.10.4:*:*:*:*:*:*:*
< 1.5.0CPE matchmatch criteria
cpe:2.3:a:amazon:amazon_web_services_internet_of_things_device_software_development_kit_v2:*:*:*:*:*:java:*:*
< 1.5.3CPE matchmatch criteria
cpe:2.3:a:amazon:amazon_web_services_internet_of_things_device_software_development_kit_v2:*:*:*:*:*:node.js:*:*
< 1.6.1CPE matchmatch criteria
cpe:2.3:a:amazon:amazon_web_services_internet_of_things_device_software_development_kit_v2:*:*:*:*:*:python:*:*
< 1.12.7CPE matchmatch criteria
cpe:2.3:a:amazon:amazon_web_services_internet_of_things_device_software_development_kit_v2:*:*:*:*:*:c\+\+:*:*

CVSS Data

CVSS version used by this source: 3.1

6.3MEDIUM

CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H

Attack Vector
ADJACENT_NETWORK
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
0.4
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.38%
Probability of exploitation in next 30 days
EPSS Percentile
30.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0037 is in the 27th percentile among its peer group of 1,875 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.2 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (3)

mavenpatch availablevia ghsa
Product: software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdkFixed in: 1.5.0
npmpatch availablevia ghsa
Product: aws-iot-device-sdk-v2Fixed in: 1.5.3
pippatch availablevia ghsa
Product: awsiotsdkFixed in: 1.6.1

Vendor Advisories (1)

mavenGHSA-c4rh-4376-gff4high

Improper certificate management in AWS IoT Device SDK v2

Nov 24, 2021

References

github.com / aws/aws-iot-device-sdk-cpp-v2
Product
github.com / aws/aws-iot-device-sdk-java-v2
Product
github.com / aws/aws-iot-device-sdk-js-v2
Product
github.com / aws/aws-iot-device-sdk-python-v2
Product
github.com / awslabs/aws-c-io
Product